This invention relates to apparatuses for minimizing oil leakage during reverse running of scroll compressors.
Scroll compressors include compressors mounted within a sealed housing structure. The sealed housing structure receives a compressor pump unit and an electric motor for driving the compressor pump unit. Refrigerant and oil are allowed to flow within the compressor housing to perform various functions such as cooling the motor, etc.
Scroll compressors are designed to operate in one direction. Gas enters the housing via a suction tube. The gas flows into compression chambers in the compressor where it is compressed and discharged via an outlet tube. If the power input lines leading from a power supply to the motor are misconnected, however, an improper phasing of the voltage may be supplied and the motor may run in reverse. In this situation, gas is being pumped from the outlet tube toward the suction tube.
During this reverse running mode, oil mixed with gas may be pumped out of the suction tube. This is undesirable, as the compressor could soon run low on oil.
Scroll compressors are typically one of two types. In a "high side" compressor, the housing section which encloses the motor is at a high pressure. The section receives compressed gas from the outlet tube. In this type compressor, the suction tube is connected directly into the scroll pump unit. Check valves have been placed on high side suction tubes.
In a "low side" compressor, the suction tube communicates with the housing portion that encloses the motor. Check valves have not been placed on the suction tube in "low side" compressors.